In recent years, portable laptop computers have become increasingly popular. Frequently, such laptop computers are battery powered in order to enhance their portability. Preferably, a battery powered laptop computer operates for an extended period of time under battery power before its battery is either recharged or replaced.
Accordingly, it is important to reduce power consumption within an electronic circuit of the laptop computer, in order to extend the period of time during which the electronic circuit operates before recharging or replacing the battery. For this purpose, some previous techniques disable power or disable clock signals to the electronic circuit in response to a specified time elapsing without sensing a particular type of activity. A shortcoming of such previous "timer" techniques is that the electronic circuit can unnecessarily consume excess power while waiting for the timer to expire, even when the electronic circuit is not performing an operation.
Another shortcoming of such techniques is that some form of interrupt is used to reenable the power or clock signals to the electronic circuit in response to an immediate need for the electronic circuit to perform an operation. Accordingly, a delay occurs between the time when the electronic circuit is needed to perform an operation and the time at which the electronic circuit is actually reenabled. Consequently, performance of the electronic circuit is sacrificed by such previous techniques, so that they are not fully transparent to a user of the electronic circuit.
Thus, a need has arisen for a method and circuitry in which an electronic circuit consumes less excess power relative to previous techniques. Also, a need has arisen for a method and circuitry in which the electronic circuit does not unnecessarily consume excess power while waiting for a timer to expire. Further, a need has arisen for a method and circuitry for reducing power consumption within an electronic circuit, in which more performance of the electronic circuit is retained relative to previous techniques. Moreover, a need has arisen for a method and circuitry for reducing power consumption within an electronic circuit, which are more fully transparent to a user of the electronic circuit relative to previous techniques.